linux/include/net/bluetooth
Schspa Shi 3b38255570 Bluetooth: When HCI work queue is drained, only queue chained work
[ Upstream commit 877afadad2 ]

The HCI command, event, and data packet processing workqueue is drained
to avoid deadlock in commit
76727c02c1 ("Bluetooth: Call drain_workqueue() before resetting state").

There is another delayed work, which will queue command to this drained
workqueue. Which results in the following error report:

Bluetooth: hci2: command 0x040f tx timeout
WARNING: CPU: 1 PID: 18374 at kernel/workqueue.c:1438 __queue_work+0xdad/0x1140
Workqueue: events hci_cmd_timeout
RIP: 0010:__queue_work+0xdad/0x1140
RSP: 0000:ffffc90002cffc60 EFLAGS: 00010093
RAX: 0000000000000000 RBX: ffff8880b9d3ec00 RCX: 0000000000000000
RDX: ffff888024ba0000 RSI: ffffffff814e048d RDI: ffff8880b9d3ec08
RBP: 0000000000000008 R08: 0000000000000000 R09: 00000000b9d39700
R10: ffffffff814f73c6 R11: 0000000000000000 R12: ffff88807cce4c60
R13: 0000000000000000 R14: ffff8880796d8800 R15: ffff8880796d8800
FS:  0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c0174b4000 CR3: 000000007cae9000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ? queue_work_on+0xcb/0x110
 ? lockdep_hardirqs_off+0x90/0xd0
 queue_work_on+0xee/0x110
 process_one_work+0x996/0x1610
 ? pwq_dec_nr_in_flight+0x2a0/0x2a0
 ? rwlock_bug.part.0+0x90/0x90
 ? _raw_spin_lock_irq+0x41/0x50
 worker_thread+0x665/0x1080
 ? process_one_work+0x1610/0x1610
 kthread+0x2e9/0x3a0
 ? kthread_complete_and_exit+0x40/0x40
 ret_from_fork+0x1f/0x30
 </TASK>

To fix this, we can add a new HCI_DRAIN_WQ flag, and don't queue the
timeout workqueue while command workqueue is draining.

Fixes: 76727c02c1 ("Bluetooth: Call drain_workqueue() before resetting state")
Reported-by: syzbot+63bed493aebbf6872647@syzkaller.appspotmail.com
Signed-off-by: Schspa Shi <schspa@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
History 2022-08-17 15:14:53 +02:00
..
bluetooth.h Bluetooth: fix incorrect nonblock bitmask in bt_sock_wait_ready() 2022-03-18 17:12:08 +01:00
hci.h Bluetooth: When HCI work queue is drained, only queue chained work 2022-08-17 15:14:53 +02:00
hci_core.h bluetooth: don't use bitmaps for random flag accesses 2022-06-05 16:28:41 -07:00
hci_mon.h Bluetooth: monitor: Add support for ISO packets 2020-01-15 22:28:51 +01:00
hci_sock.h Bluetooth: Use only 8 bits for the HCI CMSG state flags 2020-06-12 15:10:46 +02:00
hci_sync.h Bluetooth: hci_sync: Add hci_le_create_conn_sync 2021-12-22 23:01:35 +01:00
l2cap.h Bluetooth: L2CAP: Fix use-after-free caused by l2cap_chan_put 2022-07-26 13:35:24 -07:00
mgmt.h Networking changes for 5.18. 2022-03-24 13:13:26 -07:00
rfcomm.h Bluetooth: Replace zero-length array with flexible-array member 2020-02-28 08:30:02 +01:00
sco.h Bluetooth: Add support for BT_PKT_STATUS CMSG data for SCO connections 2020-06-12 15:08:49 +02:00